Digital lithography apparatus with autofocus position control and methods of use thereof

Abstract

Embodiments of the disclosure relate to digital lithography system and related methods, the system including at least one light source configured to emit a light beam onto a substrate via a lens, at least one image sensor, configured to detect a reflected light beam from the substrate via the lens, at least one motor configured to move the lens to focus the light beam onto the substrate, and a controller in communication with the at least one light source, the at least one image sensor and the at least one motor, wherein the controller is to actuate the at least one motor to move the lens in response to at least one signal from the at least one image sensor.

What is claimed is: 
     
         1 . A digital lithography system, comprising:
 at least one light source configured to emit a light beam onto a substrate via a lens;   at least one image sensor, configured to detect a reflected light beam from the substrate via the lens;   at least one motor configured to move the lens to focus the light beam onto the substrate; and   a controller in communication with the at least one light source, the at least one image sensor, and the at least one motor, wherein the controller is configured to actuate the at least one motor to move the lens in response to at least one signal from the at least one image sensor.   
     
     
         2 . The system of  claim 1 , wherein the at least one light source comprises at least one of a laser, a continuous wave (CW) laser, a quality (Q)—switched laser, or a mode-locked laser. 
     
     
         3 . The system of  claim 1 , wherein the substrate comprises at least one material of glass, a reflective material, a metal, chrome, a polymer, a crystal or an oxide. 
     
     
         4 . The system of  claim 1 , wherein the lens comprises at least one of an optical lens, a spherical lens, or an aspherical lens. 
     
     
         5 . The system of  claim 1 , wherein the at least one image sensor comprises at least one of a linear image sensor, a complementary metal oxide semiconductor (CMOS) or active pixel image sensor, a charge-coupled device (CCD) image sensor, or a solid-state device. 
     
     
         6 . The system of  claim 1 , wherein the at least one motor comprises a linear motor comprising at least one of a piezoelectric motor, an ultrasonic motor, an ultrasonic resonant motors, a piezo stepper motor, piezo-walk motor, a piezo stick-slip motor, a flexure type motor, or an inertial motor. 
     
     
         7 . The system of  claim 1 , further comprising one or more autofocus channels associated with the at least one light source and the at least one image sensor. 
     
     
         8 . The system of  claim 1 , wherein the controller is configured to actuate the at least one motor using a proportional-integral-derivative control method using autofocus signal centroids from the one or more autofocus channels as a feedback signal. 
     
     
         9 . The system of  claim 1 , wherein the controller is configured to actuate the at least one motor using a Kalman filter control method using autofocus signal centroids from the one or more autofocus channels as a feedback signal. 
     
     
         10 . The system of  claim 1 , wherein the controller is configured to actuate the at least one motor using a proportional-integral-derivative control method with dynamic channel selection using autofocus signal centroids from the one or more autofocus channels as a feedback signal. 
     
     
         11 . The system of  claim 1 , wherein the controller is configured to actuate the at least one motor using an empirical reference position control method using real-time autofocus signal centroids from the one or more autofocus channels as a feedback signal. 
     
     
         12 . A digital lithography system, comprising:
 a plurality of light sources each configured to emit a light beam onto a substrate via a lens;   a plurality of image sensors, each configured to detect a reflected light beam from the substrate via the lens, wherein each light source pairs with each image sensor;   at least one motor configured to move the lens to focus the light beam onto the substrate;   a plurality of autofocus channels each associated with at least one light source of the plurality of light sources and at least one image sensor of the plurality of image sensors; and   a controller in communication with the plurality of light sources, the plurality of image sensors and the at least one motor, wherein the controller is to actuate the at least one motor to move the lens in response to one or more signals from the plurality of image sensor.   
     
     
         13 . The system of  claim 12 , wherein the controller is to actuate the at least one motor using a proportional-integral-derivative control method using autofocus signal centroids from the one or more autofocus channels as a feedback signal; or
 wherein the controller is to actuate the at least one motor using a Kalman filter control method using autofocus signal centroids from the one or more autofocus channels as a feedback signal; or   wherein the controller is to actuate the at least one motor using a proportional-integral-derivative control method with dynamic channel selection using autofocus signal centroids from the one or more autofocus channels as a feedback signal; or   wherein the controller is to actuate the at least one motor using an empirical reference position control method using real-time autofocus signal centroids from the one or more autofocus channels as a feedback signal.   
     
     
         14 . A method of automatically focusing a light beam in a digital lithography system, comprising:
 directing at least one light beam from at least one light source onto a substrate via a lens;   reflecting the at least one light beam from the substrate through the lens and to at least one image sensor;   receiving by a controller at least one signal from the at least one image sensor, wherein the at least one signal indicates a position of the light beam on the substrate; and   controlling by the controller a position of the lens to focus the light beam onto a surface of the substrate.   
     
     
         15 . The method of  claim 14 , further comprising, calibrating the at least one image sensor to correlate a change in length (ΔL) of the reflected light beam along a length of the at least one image sensor with a change in height (ΔZ) of the surface of the substrate. 
     
     
         16 . The method of  claim 14 , wherein controlling the position of the lens comprises actuating at least one motor to move the lens. 
     
     
         17 . The method of  claim 16 , wherein controlling the position of the lens comprises:
 actuating by the controller the at least one motor using a proportional-integral-derivative control method using autofocus signal centroids from the one or more autofocus channels as a feedback signal; or   actuating the at least one motor using a Kalman filter control method using autofocus signal centroids from the one or more autofocus channels as a feedback signal; or   actuating the at least one motor using a proportional-integral-derivative control method with dynamic channel selection using autofocus signal centroids from the one or more autofocus channels as a feedback signal; or   actuating the at least one motor using an empirical reference position control method using real-time autofocus signal centroids from the one or more autofocus channels as a feedback signal.   
     
     
         18 . The method of  claim 16 , wherein the at least one motor is a linear motor selected from the group consisting of a piezoelectric motor, an ultrasonic motor, an ultrasonic resonant motors, a piezo stepper motor, piezo-walk motor, a piezo stick-slip motor, a flexure type motor and an inertial motor. 
     
     
         19 . The method of  claim 14 , wherein the substrate comprises at least one material selected from the group consisting of glass, a reflective material, a metal, chrome, a polymer, a crystal or an oxide. 
     
     
         20 . The method of  claim 14 , wherein the at least one image sensor is selected from the group consisting of a linear image sensor, a complementary metal oxide semiconductor (CMOS) or active pixel image sensor, a charge-coupled device (CCD) image sensor and a solid-state device.